111. 4—111. 5. 71 



The heart is of large size^'^ in the hare, the deer, the mouse, 

 the hyaena, the ass, the leopard, the marten, and in pretty nearly 

 all other animals that are either manifestly timorous, or that 

 betray their cowardice by their spitefulness. 



What has been said of the heart as a whole is no less true of its 

 cavities and of the blood-vessels ; these also if of large size being 

 cold.^3 For just as a fire of equal size gives less heat in a large 

 room than in a small one, so also does the heat in a large cavity 

 or a large blood-vessel, that is in a large receptacle, have less 

 influence than in a small one. The more spacious, moreover, these 

 cavities and vessels are, the greater is the amount of spirit ^ which 

 they contain, and the greater its effect, for all hot substances are 

 cooled by the motion of external objects,^^ Thus it is that no 

 animal that has large cavities in its heart, or large blood-vessels, 

 is ever fat, the vessels being indistinct and the cavities small in 

 all or most fat animals.^^ 



The heart again is the only one of the viscera, and indeed the 

 only part of the body, that is unable to tolerate any serious affec- 

 tion.^''' This is but what might reasonably be expected. For, if 

 the primary or dominant part be diseased, there is nothing from 

 which the other parts which depend upon it can derive succour. 

 A proof, that the heart is thus unable to tolerate any morbid 

 affection, is furnished by the fact that never has it been seen 

 diseased in a sacrificial victim, though this is not the case with 

 the other viscera. For the kidneys are frequently found to be 

 full of stones, and growths, and small abscesses, as also is 'the 

 liver, the lung, and more than all the spleen.^^ There are also 

 many other affections which are seen to occur in these parts, those 

 which are least liable to such being the portion of the lung which 

 is close to the windpipe, and the portion of the liver which lies 

 about the junction with the great blood-vessel. This again admits 

 of a rational explanation. For it is in these parts that the lung 

 and liver are most closely in communion with the heart. On the 

 other hand when animals die not by sacrifice but from disease, 

 they are found on dissection to have morbid affections of the heart. 



(Ch. 5. J Thus much of the heart, its nature, and the end and 

 cause of its existence in such animals as have it. In due sequence 

 we have next to discuss the blood-vessels, that is to say the great 

 vessel and the aorta. For it is into these two^ that the blood 

 first passes when it quits the heart; and all the other vessels 

 667 b. 



